Aging cesspools and septic systems in waterfront communities like Flanders and Riverside are likely to fail in the future and could affect water quality, the executive director of Peconic Green Growth told the Flanders, Riverside and Northside Community Association Monday night.

Glynis Berry has been seeking a community on the East End that would be willing to be part of a pilot program for a decentralized wastewater treatment system to protect surface water and drinking water, and suggested Flanders, and in particular, the Bayview Pines area, as a candidate. Peconic Green Growth is a Riverhead-based non-profit.

“We realized nobody was looking at site specific water treatment for environmental conditions, it was all about drinking water,” she said at Monday’s FRNCA meeting.

The nitrogen standards for drinking water are actually less stringent than those for surface water, she said.

But increased nitrogen levels are harming the surface waters by causing algae blooms, which in turn eat up oxygen and lead to the demise of shellfish and eel grass, she said.

With many older homes using either cesspools or aging septic systems, a waterfront area like Bayview Pines is prone for future problems as the water table rises, Ms. Berry said.

Peconic Green Growth, a Riverhead-based non-profit, is looking for a community with about 200 to 500 homes to evaluate and determine what types of sewage treatment systems make sense in that neighborhood and what the costs will be.

“We are looking for neighborhoods that are open to it, so we can see if we can actually get a pilot project in the ground,” said Ms. Berry, who is an architect, urban designer and planner.

She said she has secured grant money for the project but is looking for a community willing to participate.

She’s also taking a survey asking questions about the type and age of people’s cesspools or septic systems and how much people would be willing to pay.

About 40 percent of the respondents so far said they’d be willing to spend $500 a year for a sewage treatment system that improves water quality.